Soy-modified resins for bonding wood

Abstract

Engineered wood products and binder compositions are provided. In preferred embodiments, the engineered wood products include wax. Methods are also provided for formulating binders for wood comprising unmodified soy flour and synthetic adhesives. The soy-based formulations are prepared by mixing unmodified soy flour with the synthetic adhesive prior to application to the wood or by adding them sequentially to the wood. The present invention provides adequate bonding at reduced cost.

What is claimed is: 
     
       1. A method of preparing a pressed wood composite comprising:
 heating a binder composition, wherein the binder composition comprises unmodified soy product and a synthetic resin; wherein the synthetic resin comprises MDI; 
 applying a binder composition to a lignocellulosic material to form a mixture, wherein the soy product is between about 1 wt. % and about 50 wt. % of the binder composition, wherein the binder has a viscosity of less than about 1000 cp; 
 forming the mixture into a mat; and 
 pressing the mat while simultaneously heating the mat to form a pressed wood composite;
 wherein the pressed wood composite is a chipboard, a medium density fiberboard, a high density fiberboard, a flake board, a laminated-strand lumber, an oriented strand board, a parallel-strand lumber, a particle board, a plywood, a veneer, or a wafer board. 
 
 
     
     
       2. The method of  claim 1 , wherein the unmodified soy product is selected from the group consisting of soy flour, soy meal, and a mixture thereof; wherein the synthetic resin further comprises PF, UF, or a mixture thereof; and wherein the binder composition is applied at a dosage of 0.5% to 20% by weight of wood. 
     
     
       3. The method of  claim 2 , further comprising a step of adding wax to the lignocellulosic materials prior to the mixing step. 
     
     
       4. The method of  claim 2 , wherein the binder composition is applied to core layers of the mat with an unmodified synthetic resin applied to the face layers of the mat. 
     
     
       5. The method of  claim 2 , wherein the soy flour and the synthetic binder composition is applied to face layers of the mat with an unmodified synthetic resin applied to the core layers of the mat. 
     
     
       6. The method of  claim 1 , wherein the soy product is between about 10 wt. % and about 50 wt. % of the binder composition. 
     
     
       7. The method of  claim 1 , wherein the applying step is performed by spraying the binder on the lignocellulosic material, and wherein the binder has a viscosity of between about 250 cp and about 750 cp. 
     
     
       8. A method of preparing a pressed wood composite comprising:
 (a) mixing an unmodified soy product with lignocellulosic material, 
 (b) adding a synthetic resin to the unmodified soy product with lignocellulosic material to form a mixture, wherein the unmodified soy product and synthetic resin form a binder composition, and wherein the unmodified soy product is in an amount less than about 20 wt. % of the binder composition; wherein the synthetic resin comprises MDI; 
 (c) forming the mixture into a mat; and 
 (d) pressing the mat while simultaneously heating the mat to form a pressed wood composite; 
 
       wherein the steps (a) through (d) are performed sequentially; and wherein the pressed wood composite is a chipboard, a medium density fiberboard, a high density fiberboard, a flake board, a laminated-strand lumber, an oriented strand board, a parallel-strand lumber, a particle board, a plywood, a veneer, or a wafer board. 
     
     
       9. The method of  claim 8 , wherein the unmodified soy product is selected from the group consisting of soy flour, soy meal, and a mixture thereof; wherein the synthetic resin further comprises PF, UF, or a mixture thereof; and wherein the binder composition is applied at a dosage of 0.5% to 20% by weight of wood. 
     
     
       10. The method of  claim 9 , further comprising a step of adding wax to the lignocellulosic materials prior to step (a). 
     
     
       11. The method of  claim 9 , wherein the binder composition is applied to core layers of the mat with an unmodified synthetic resin applied to the face layers of the mat; or wherein the soy flour and the synthetic binder composition is applied to face layers of the mat with an unmodified synthetic resin applied to the core layers of the mat. 
     
     
       12. A method of preparing a pressed wood composite comprising:
 heating a binder composition, wherein the binder composition comprises unmodified soy product and synthetic resin, wherein the synthetic resin comprises MDI, and wherein the binder composition has a viscosity of less than about 1000 cp; 
 spraying the binder composition on a lignocellulosic material to form a mixture; 
 forming the mixture into a mat; 
 pressing the mat while simultaneously heating the mat to form a pressed wood composite;
 wherein the pressed wood composite is a chipboard, a medium density fiberboard, a high density fiberboard, a flake board, a laminated-strand lumber, an oriented strand board, a parallel-strand lumber, a particle board, a plywood, a veneer, or a wafer board. 
 
 
     
     
       13. The method of  claim 12 , wherein the binder composition has a viscosity of between about 250 cp and about 750 cp. 
     
     
       14. The method of  claim 12 , wherein the unmodified soy product is in an amount less than about 20 wt. % of the binder composition. 
     
     
       15. The method of  claim 12 , wherein the unmodified soy product is in an amount between about 10 wt. % to about 15 wt. % of the binder composition. 
     
     
       16. The method of  claim 12 , wherein the binder composition is sprayed on the lignocellulosic material within 2 minutes of the creation of the binder composition. 
     
     
       17. The method of  claim 12 , wherein the binder composition is sprayed on the lignocellulosic material within 10 seconds of the creation of the binder composition. 
     
     
       18. The method of  claim 12 , wherein the binder composition further comprises one or more of the following functional ingredients: a dye, a pigment, a processing aid, a reinforcing agent, a filler, an oil, a viscosity-modifying agent, a wax, and water.